18 U.S.C. § 209: Salary of Government officials and employees payable only by United States

This statute prohibits employees from being paid by someone other than the United States for doing their official Government duties. For example, a highly paid executive of a corporation, upon entering Government service, could not accept an offer from her former employer to make up the difference between her Government salary and the compensation she received from her former employer. The prohibition does not apply to:

special Government employees and employees serving without compensation

funds contributed out of the treasury of any State, county, or municipality

continued participation in a bona fide pension, retirement, group life, health or accident insurance, profit-sharing, stock bonus, or other employee welfare or benefit plan maintained by a former employer

payments for travel, subsistence and other expenses made to an employee by a tax-exempt nonprofit organization incurred in connection with training

moving expenses incurred in connection with participation in an executive exchange or fellowship program in an executive agency.